This application is a national entry filing of PCT/US2013/075454, filed Dec. 16, 2013, hereby expressly incorporated herein by reference, and also claims the priority benefit of US provisional application Serial No. 61/737,288, filed Dec. 14, 2012, which is also hereby expressly incorporated herein by reference.
The present exemplary embodiment relates to high-strength cable attachments for dynamic applications, and finds particular use in connection with wide-tow and/or high-load seismic surveys. For example, the present disclosure finds particular application in conjunction with mid-span cable attachments and for connecting paravanes, compressors and floats, lines, and light packages to cable spans, and will be described with particular reference thereto. However, it is to be appreciated that the present exemplary embodiments are also amenable to other like applications.
For example, today's three-dimensional (3D) seismic operators tow sixteen (16) or more streamers to provide large amounts of data to meet the demands required in connection with seismic mapping. As a result, a need exists for lead-in line protection for the cable, and a low profile, full strength seismic lead termination design that can effectively grip a towed cable. In particular, the termination must be able to be installed mid-span at any location on the lead-in and be conveniently designed so the termination can be wound on to a cable drum.
The assignee of the present application presently sells a commercial unit known as a Dyna-Hanger Suspension System (DHSS). The DHSS is a reliable cable attachment point for seismic streamers, paravanes, surface and subsurface floats, cable compressors, and other instances requiring mid-span termination. The commercially available DHSS provides for two degrees of freedom with respect to the cable axis. Particularly, a collar assembly can rotate 360° around the cable to provide a first degree of freedom, and a pair of trunnion-mounted arms articulates fore and aft to provide a second degree of freedom. As a result, the lead-in can rotate and the arms of the DHSS can become aligned with the load. When stored on deck, the collar assembly of the DHSS is removed to allow the housing and rods to be reeled directly on to a cable drum.
Although the DHSS has met with commercial success, there are continued needs for improvement. For example, ease of assembly/disassembly, an increased number of degrees of freedom, modularity, subassemblies, reliability, strength, ease of manufacture and efficiency of manufacture, limiting the number of tools required for assembly and disassembly, reduced drag, adaptability to different configurations, reduced cost, etc. are just some of the desired needs, although it will be recognized that this list is not deemed to be limiting or exhaustive.